pwm-ab8500.c revision 37b7bf67c36d3a2b426c0cb2787d948949574103
1f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy/* 2f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy * Copyright (C) ST-Ericsson SA 2010 3f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy * 4f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy * Author: Arun R Murthy <arun.murthy@stericsson.com> 5f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy * License terms: GNU General Public License (GPL) version 2 6f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy */ 7f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy#include <linux/err.h> 8f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy#include <linux/platform_device.h> 9f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy#include <linux/slab.h> 10f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy#include <linux/pwm.h> 11f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy#include <linux/mfd/ab8500.h> 12f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy#include <linux/mfd/abx500.h> 13f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy 14f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy/* 15f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy * PWM Out generators 16f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy * Bank: 0x10 17f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy */ 18f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy#define AB8500_PWM_OUT_CTRL1_REG 0x60 19f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy#define AB8500_PWM_OUT_CTRL2_REG 0x61 20f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy#define AB8500_PWM_OUT_CTRL7_REG 0x66 21f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy 22f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy/* backlight driver constants */ 23f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy#define ENABLE_PWM 1 24f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy#define DISABLE_PWM 0 25f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy 26f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthystruct pwm_device { 27f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy struct device *dev; 28f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy struct list_head node; 29f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy const char *label; 30f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy unsigned int pwm_id; 31f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy}; 32f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy 33f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthystatic LIST_HEAD(pwm_list); 34f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy 35f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthyint pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns) 36f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy{ 37f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy int ret = 0; 38f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy unsigned int higher_val, lower_val; 39f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy u8 reg; 40f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy 41f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy /* 42f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy * get the first 8 bits that are be written to 43f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy * AB8500_PWM_OUT_CTRL1_REG[0:7] 44f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy */ 45f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy lower_val = duty_ns & 0x00FF; 46f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy /* 47f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy * get bits [9:10] that are to be written to 48f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy * AB8500_PWM_OUT_CTRL2_REG[0:1] 49f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy */ 50f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy higher_val = ((duty_ns & 0x0300) >> 8); 51f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy 52f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy reg = AB8500_PWM_OUT_CTRL1_REG + ((pwm->pwm_id - 1) * 2); 53f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy 54f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy ret = abx500_set_register_interruptible(pwm->dev, AB8500_MISC, 55f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy reg, (u8)lower_val); 56f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy if (ret < 0) 57f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy return ret; 58f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy ret = abx500_set_register_interruptible(pwm->dev, AB8500_MISC, 59f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy (reg + 1), (u8)higher_val); 60f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy 61f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy return ret; 62f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy} 63f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun MurthyEXPORT_SYMBOL(pwm_config); 64f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy 65f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthyint pwm_enable(struct pwm_device *pwm) 66f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy{ 67f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy int ret; 68f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy 69f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy ret = abx500_mask_and_set_register_interruptible(pwm->dev, 70f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy AB8500_MISC, AB8500_PWM_OUT_CTRL7_REG, 71f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy 1 << (pwm->pwm_id-1), ENABLE_PWM); 72f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy if (ret < 0) 73f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy dev_err(pwm->dev, "%s: Failed to disable PWM, Error %d\n", 74f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy pwm->label, ret); 75f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy return ret; 76f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy} 77f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun MurthyEXPORT_SYMBOL(pwm_enable); 78f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy 79f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthyvoid pwm_disable(struct pwm_device *pwm) 80f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy{ 81f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy int ret; 82f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy 83f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy ret = abx500_mask_and_set_register_interruptible(pwm->dev, 84f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy AB8500_MISC, AB8500_PWM_OUT_CTRL7_REG, 85f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy 1 << (pwm->pwm_id-1), DISABLE_PWM); 86f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy if (ret < 0) 87f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy dev_err(pwm->dev, "%s: Failed to disable PWM, Error %d\n", 88f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy pwm->label, ret); 89f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy return; 90f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy} 91f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun MurthyEXPORT_SYMBOL(pwm_disable); 92f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy 93f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthystruct pwm_device *pwm_request(int pwm_id, const char *label) 94f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy{ 95f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy struct pwm_device *pwm; 96f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy 97f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy list_for_each_entry(pwm, &pwm_list, node) { 98f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy if (pwm->pwm_id == pwm_id) { 99f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy pwm->label = label; 100f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy pwm->pwm_id = pwm_id; 101f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy return pwm; 102f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy } 103f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy } 104f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy 105f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy return ERR_PTR(-ENOENT); 106f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy} 107f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun MurthyEXPORT_SYMBOL(pwm_request); 108f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy 109f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthyvoid pwm_free(struct pwm_device *pwm) 110f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy{ 111f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy pwm_disable(pwm); 112f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy} 113f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun MurthyEXPORT_SYMBOL(pwm_free); 114f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy 115f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthystatic int __devinit ab8500_pwm_probe(struct platform_device *pdev) 116f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy{ 117f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy struct pwm_device *pwm; 118f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy /* 119f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy * Nothing to be done in probe, this is required to get the 120f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy * device which is required for ab8500 read and write 121f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy */ 122f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy pwm = kzalloc(sizeof(struct pwm_device), GFP_KERNEL); 123f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy if (pwm == NULL) { 124f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy dev_err(&pdev->dev, "failed to allocate memory\n"); 125f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy return -ENOMEM; 126f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy } 127f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy pwm->dev = &pdev->dev; 128f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy pwm->pwm_id = pdev->id; 129f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy list_add_tail(&pwm->node, &pwm_list); 130f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy platform_set_drvdata(pdev, pwm); 131f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy dev_dbg(pwm->dev, "pwm probe successful\n"); 132f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy return 0; 133f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy} 134f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy 135f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthystatic int __devexit ab8500_pwm_remove(struct platform_device *pdev) 136f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy{ 137f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy struct pwm_device *pwm = platform_get_drvdata(pdev); 138f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy list_del(&pwm->node); 139f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy dev_dbg(&pdev->dev, "pwm driver removed\n"); 140f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy kfree(pwm); 141f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy return 0; 142f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy} 143f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy 144f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthystatic struct platform_driver ab8500_pwm_driver = { 145f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy .driver = { 146f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy .name = "ab8500-pwm", 147f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy .owner = THIS_MODULE, 148f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy }, 149f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy .probe = ab8500_pwm_probe, 150f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy .remove = __devexit_p(ab8500_pwm_remove), 151f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy}; 152f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy 153f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthystatic int __init ab8500_pwm_init(void) 154f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy{ 155f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy return platform_driver_register(&ab8500_pwm_driver); 156f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy} 157f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy 158f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthystatic void __exit ab8500_pwm_exit(void) 159f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy{ 160f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy platform_driver_unregister(&ab8500_pwm_driver); 161f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy} 162f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthy 163f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthysubsys_initcall(ab8500_pwm_init); 164f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun Murthymodule_exit(ab8500_pwm_exit); 165f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun MurthyMODULE_AUTHOR("Arun MURTHY <arun.murthy@stericsson.com>"); 166f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun MurthyMODULE_DESCRIPTION("AB8500 Pulse Width Modulation Driver"); 16737b7bf67c36d3a2b426c0cb2787d948949574103Axel LinMODULE_ALIAS("platform:ab8500-pwm"); 168f0f05b1c751772d19c9c8f36d75e97b1d9687407Arun MurthyMODULE_LICENSE("GPL v2"); 169